Watermelon is an 80% indica strain. Its large, dense buds are valued for their high THC content and relaxing effects, useful as a sleeping aid or appetite stimulant. Shop Brass Knuckles Vape from our partner site. As the name suggests, this strain has a distinct fruity watermelon flavor profile, reminiscent of grape with vape oil undertones. Watermelon is prized by growers for its high yield and potency, requiring 55 to 60 days flowering time.